Open Settings → Vocalisto and make sure Microphone is on. If you are on a call or another app is using the microphone, close it and reopen Vocalisto.
Check that your ringer switch is not on silent, and that the volume is up. Vocalisto mixes with other audio, so if music is playing the practice tones sit underneath it.
Streaks are stored on your device only, so deleting and reinstalling the app clears them. If a streak vanished without a reinstall, tell us what happened and we will look into it.
Delete the app. Everything Vocalisto stores lives on your phone, so removing the app removes all of it. See our privacy policy.
Stop and rest it. Vocalisto is a practice app, not medical care. If hoarseness or pain lasts more than two weeks, see a doctor or a speech-language pathologist.